Bonding may be used for manufacturing items with laminar, interlocking, or other distinct components. For example, various layers of solar cells may be bonded together. Wafers and other substrates may be bonded, as may subassemblies and complete devices.
Polymer adhesives and industrial-grade adhesive films may create strong, uniform attachments between a variety of materials and surface profiles. Items can be bonded by polymer adhesives whether or not the mating surfaces are smooth or the contours fit together perfectly. Some adhesives provide a somewhat flexible bond between materials with different coefficients of thermal expansion. Material and capital costs may be lower for adhesives than for other bonding methods.
Most adhesives are intrinsically insulating, both electrically and thermally, which is often advantageous. Yet, there are some applications for which an electrically or thermal conductive bond is desired. One adaptation has been the introduction of anisotropic conducting adhesives with conducting particles that form conductive paths between the mating surfaces. The primary design trade-off in formulating anisotropic conducting adhesives is between (1) higher particle density for higher conductivity or (2) lower particle density for smoother flow, better adhesion, and more resilience under thermal or mechanical stress.